Wafer double-side polishing apparatus and method of evaluating the same

A wafer double-side polishing apparatus evaluation method comprising:

• preparing a wafer double-side polishing apparatus comprising an upper plate and a lower plate facing each other, polishing pads respectively disposed at a lower portion of the upper plate and at an upper portion of the lower plate, a first gear disposed in a central region of an upper surface of the lower plate, a second gear disposed in a peripheral region of the upper surface of the lower plate, and carriers disposed between the polishing pads while being engaged between the first gear and the second gear, the upper plate comprising a plurality of slurry supply holes extending in a vertical direction, each of the carriers comprising at least one wafer accommodation hole;
• accommodating wafers in the wafer accommodation holes of the carriers, respectively, supplying slurry through the slurry supply holes, and polishing the wafers by friction thereof with the polishing pads disposed pads disposed thereover and thereunder;
• and
• comparing a B/A value with a global backside ideal plane range (GBIR),
• wherein “A” is a cross-sectional area of the lower plate, “B” is a sum of cross-sectional areas of the wafer accommodation holes formed at the carriers, and “GBIR” represents a height difference between a highest portion and a lowest portion of a surface of each wafer.